User Manual
634
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
UART1/UART2
The baud rate range defined by different BGSEL settings is shown in
.
Each BGSEL setting supports a range of baud rate for detection. If the baud rate used is outside the defined
range, the baud rate may not be detected correctly.
When
f
sys
= 40 MHz, the baud rate range between 18.3 kHz to 555.6 kHz can be detected. The following
examples serve as a guide to select the BGSEL value:
• If the baud rate falls in the range of 2.3 kHz to 4.6 kHz, selected BGSEL value is “11
B
”.
• If the baud rate falls in the range of 4.6 kHz to 9.2 kHz, selected BGSEL value is “10
B
”.
• If the baud rate falls in the range of 9.2 kHz to 18.3 kHz, selected BGSEL value is “01
B
”.
• If the baud rate falls in the range of 18.3 kHz to 555.6 kHz, selected BGSEL value is “00
B
”.
• If the baud rate is 20 kHz, the possible values of BGSEL that can be selected are “00
B
”, “01
B
”, “10
B
”, and
“11
B
”. However, it is advisable to select “00
B
” for better detection accuracy.
The baud rate can also be detected when
f
sys
= 25 MHz, for which the baud rate range that can be detected is
between 1.4 kHz to 347.2 kHz.
In general, BGSEL should be selected as small as possible, to achieve the best possible accuracy.
Table 334 BGSEL Bit Field Definition for Different Input Frequencies
f
sys
BGSEL
Baud Rate Select for Detection
f
sys
/(2184*2
BGSEL
) to
f
sys
/(72*2
BGSEL
)
40 MHz
00
B
18.3 kHz to 555.6 kHz
01
B
9.2 kHz to 277.8 kHz
10
B
4.6 kHz to 138.9 kHz
11
B
2.3 kHz to 69.4 kHz
25 MHz
00
B
11.2 kHz to 347.2 kHz
01
B
5.7 kHz to 173.6 kHz
10
B
2.9 kHz to 86.8 kHz
11
B
1.4 kHz to 43.4 kHz